Returns the current execution stack—an array containing strings in
the form ``file:line’‘ or ``file:line: in
`method’’’. The optional start parameter
determines the number of initial stack entries to omit from the result.

In Ruby 1.8.7, the reported method names were those of the methods actually
invoked, so if #b was an alias for #a, and #b was called, it would be
reported as “… in `b’”. In Ruby 1.9, the same invocation is now
reported as “… in `a’”.

Unfortunately, this change disables the hack that could formerly be used to
create a variant of __method__ that
returns the method as actually invoked. The new __callee__ method is no help with that,
because it is currently synonymous with __method__.